--- a/util/datamapper.lua	Tue Mar 23 21:52:07 2021 +0100
+++ b/util/datamapper.lua	Tue Mar 23 23:55:33 2021 +0100
@@ -13,6 +13,9 @@
 end
 
 local function totype(t, s)
+	if not s then
+		return nil
+	end
 	if t == "string" then
 		return s
 	elseif t == "boolean" then